Hydrogen for Energy Storage Analysis Overview (Presentation)

1 NREL is a national laboratory of the Department of Energy , Office of Energy Efficiency and Renewable Energy , operated bythe Alliance for Sustainable Energy , for Energy Storage Analysis OverviewNational Hydrogen Association Conference & ExpoDarlene Steward, Todd Ramsden, Kevin HarrisonNational Renewable Energy LaboratoryMay 3-6, 2010 Long Beach, CANREL/PR-560-48360 This presentation does not contain any proprietary, confidential, or otherwise restricted information2 National Renewable Energy Laboratory Innovation for Our Energy FutureObjectivesCompare Hydrogen and competing technologies for utility-scale Energy Storage the cost and GHG emissions impacts of interaction of Hydrogen Storage and variable renewable resourcesOutlineStudy FrameworkPreliminary Study Results Lifecycle cost Analysis for Hydrogen and competing technologies GHG emissions credit

2 Impact for a remote wind farmNREL Wind to Hydrogen Study PerspectivesHydrogen Energy Storage System Modeling23 Scenarios for Hydrogen Energy Storage AnalysesNational Renewable Energy Laboratory Innovation for Our Energy Future3 BatteryElectricityPump/Compressor/Turbin eElectricityAir or Water Reservoir?Is Hydrogen a potential solution for utility-scale Energy storageShed electricity?How would using Hydrogen for Storage impact cost and emissions for renewable resourcesHydrogen StorageShed electricityComparison of costs for Hydrogen and competing technologiesStudy of Hydrogen Energy Storage for a specific renewable resource4 Energy Storage Scenario for Comparison StudyNominal Storage volume is 300 MWh(50 MW, 6 hours)oElectricity is produced from the Storage system during 6 peak hours (1 to 7 pm) on weekdaysoElectricity is purchased during off-peak hours to charge the system Electricity source.

3 Excess wind/off-peak grid electricity oAssumed steady and unlimited supply during off-peak hours (18 hours on weekdays and 24 hours on weekends)oAssumed fixed purchase price of off-peak/renewable electricitySource: HOMER model outputNational Renewable Energy Laboratory Innovation for Our Energy Future5 levelized cost of Hydrogen and Competing TechnologiesHydrogen is competitive with batteries and could be competitive with CAESand pumped hydro in locations that are not favorable for these Renewable Energy Laboratory Innovation for Our Energy Future56 National

4 Renewable Energy Laboratory Innovation for Our Energy FutureRound-Trip Efficiency and Electricity Price Sensitivity Electricity price sensitivityoLow-capital- cost , high-efficiency pumped hydro system is sensitive to electricity priceoHigh-capital- cost NiCd system is insensitive to electricity priceoFor other Storage systems, sensitivity to electricity price is roughly inversely proportional to round-trip efficiency NiCd batteryCAESFC abovegroundPumped hydroFC/geologicH2 Comb turbineNaS batteryVR System Round-Trip EfficiencyElectricity Price Sensitivity (% change in LCE/c)

5 National Renewable Energy Laboratory Innovation for Our Energy Future7 National Renewable Energy Laboratory Innovation for Our Energy FutureEnergy Storage & Greenhouse GasesSource: Denholm, Paul. (October 2006). Creating Baseload Wind Power Systems Using Advanced Compressed Air Energy Storage Concepts. Poster presented at the University of Colorado Energy Initiative/NREL Symposium.

6 +-Additional Energy from the windfarm can be captured for later useEfficiency losses incurred by routing wind Energy through the Storage system reduce the greenhouse gas benefit of wind8 Wind Farm Location8 National Renewable Energy Laboratory Innovation for Our Energy FutureThe NREL Western Wind Data Set was used to identify a realistic remote wind farm location9 Study Framework - Add Hydrogen Storage to a Base Case Without StorageNational Renewable Energy Laboratory Innovation for Our Energy Future750 MWHydrogen Storage400 MTCurtailed electricity 2%Electricity to grid ( Storage + direct)87% of total wind farm outputStorage Constrained CaseElectricity to storage16% of total wind farm outputElectricity from storage5% of total output500 MWHydrogen Storage2,600 MTCurtailed electricity 12%( Storage + direct)

7 68% of total wind farm outputTransmission Constrained CaseElectricity to storage27% of total wind farm outputElectricity from storage7% of total outputCurtailed electricity 17%Electricity to grid83%750 MWBase Case (without Storage )9 National Renewable Energy Laboratory Innovation for Our Energy FutureAnalysis of the base case provides LCOE and avoided emissions for comparison10 National Renewable Energy Laboratory Innovation for Our Energy FuturePrimary Study AssumptionsMajor AssumptionsoElectrolyzerand PEM fuel cell performance and cost values derived from mid- cost case of

8 Lifecycle cost analysisoHydrogen Storage in geologic storageoThe Storage system is located at the wind farm & all electricity charged to the Storage system is derived from the wind farmoA dedicated transmission line carries electricity from the wind farm/ Storage system to the grid near demand from the wind farm will be curtailed (shed) if:oIt exceeds the maximum charging rate of the Storage system + maximum capacity of the transmission lineoThe Storage system is fullNational Renewable Energy Laboratory Innovation for Our Energy FutureHydrogen StorageShed electricity1011 National Renewable Energy Laboratory Innovation for Our Energy FutureWind Farm and Hydrogen Storage for Storage

9 Constrained Case - Hydrogen to StorageNational Renewable Energy Laboratory Innovation for Our Energy Future1105,00010,00015,00020,00025,00030 ,0001/2/062/2/063/2/064/2/065/2/066/2/06 7/2/068/2/069/2/0610/2/0611/2/0612/2/06 Energy (MWh/day)Electricity From Wind (kW) Hydrogen to Storage (kW)12 National Renewable Energy Laboratory Innovation for Our Energy FutureWind Farm and Hydrogen Storage for Storage Constrained Case - Hydrogen from StorageNational Renewable Energy Laboratory Innovation for Our Energy Future1205,00010,00015,00020,00025,00030 .

10 0001/2/062/2/063/2/064/2/065/2/066/2/067 /2/068/2/069/2/0610/2/0611/2/0612/2/06 Energy (MWh/day)Electricity FromWind (kW) Hydrogen fromStorage (kW)13 Summary of Preliminary ResultsNational Renewable Energy Laboratory Innovation for Our Energy FutureStorage reduces the amount of electricity that must be curtailed and reduces the LCOEBase CaseStorage ConstrainedTransmission ConstrainedElec t ric it y Direc t from Wind Farm t o T ransmission t ric it y from St t ric it y Shed Electricity